Thermoplastic yarns, methods of producing same, and products knit therefrom



Oct. 29, 1957 F. w. SlLVER I 2,81

THERMOPLASTIC YARNS, METHODS OF. PRODUCING SAME AND PRODUCTS KNIT THEREFROM 3 Sheets-Sheet 1 Filed Dec. 10, 1954 INVENTOR.

F W 6/L V62 IDMW Oct. 29, 1957 F. w. SILVER 2,810,949

' THERMOPLASTIC YARNS, METHODS OF PRODUCING SAME AND PRODUCTS KNIT THEREFROM Filed Dec: 10, 1954 3 Sheets-Sheet 2 Mrs/W02 F W 51.41 69 mmwwa Oct. 29, 1957 F. w. SILVER 2,810,949

THERMOPLASTIC YARNS, METHODS OF PRODUCING SAME AND PRODUCTS KNIT THEREFROM Filed Dec. 10, 1954 5 Sheets-Sheet 3 fiws/vroz E W. SIL 1/5? MMAAQM urn ey:

United States Patent '0 f THERP ZGFLASTHJ YARNS, METHODS OF PRO- DUCING SAME, AND PRODUCTS KNIT THERE- FRQM Frederick William Silver, Columbus, Ga., assignor to Archer Mills, Inc., Columbus, Ga., a corporation of Georgia Application December 10, 1954, Serial No. 474,317

38 Claims. (Cl. 28-78) The present invention relates to thermoplastic yarns, methods of producing same and products knit therefrom and has for an object to provide a new thermoplastic yarn having high stretch characteristics and providing a sheer smooth appearance at the same time.

It is contemplated that the yarn of the instant invention be employed in knitting a fabric for full fashion hosiery, socks for men, or other fabrics requiring a high degree of stretch.

Heretofore in the knitting and weaving art it has been known to take yarn of multiple filaments and to process the same in accordance with the teachings of the Helanca processes as exemplified in the Billion Patent No. 2,564,245. I have found in practice that yarn constructed in accordance with the teaching of Billion and others has proven unsatisfactory particularly in the knitting of womens full fashion hosiery because of the bulk imparted thereto and the lack of sheerness.

I propose to prepare the yarn from monofilaments of a synthetic thermoplastic material for example nylon being a synthetic linear polyamide or Dacron being a synthetic linear condensation polyester yarn. As stated above the Billion patent and others in this field have prepared their yarns from multiple strand yarn ends. The yarn prepared according to my invention is extruded from a single orifice die as distinguished from the multiple orifice die employed in extruding multiple filament yarns.

I propose preparing a yarn having a high degree of stretch and return for purposes of conforming to varying surfaces to be covered thereby.

A still further object of the present invention is to provide a single combined yarn which is knit into a fabric by employing a single carrier to provide a clear sheer fabric as distinguished from two or more threads requiring multiple carrier knitting which is undesirable in sheer full fashion hosiery.

A further object of the present invention is to provide a means for stabilizing the yarn produced in accordance with the present invention in order to render the same more knittable or weavable. When nylon or Dacron yarns are twisted there is imparted thereto a certain degree of wildness and this results in appreciable difiiculty in the knitting or weaving of this yarn. I propose the use of a stabilizer to render thi thread more knittable. The stabilizer may for example be a non thermoplastic thread or yarn or it may be either a fiber or a size such as P. M. 90 (polyvinyl acetate) which may be subsequently removed from the thermoplastic yarn after the knitting or weaving process without detrimentally aflecting the thermoplastic yarn. By way of example such a stabilizer may be a silk thread of the order of 13/15. The stabilizer may be dissolved out.

A still further object of my invention is to provide a yarn of two twisted monofils plied to produce a single combined yarn having balance and stretch with good recovery and which may be knitted into a fabric with a single carrier.

The basic material from which the yarn is prepared I Patented Oct. 29, 1957 ice will be a thermoplastic thread such as nylon or any other suitable synthetic thermoplastic yarn and for example may be of two 7-denier monofilament threads or yarn.

One of the pre-set (the pre-setting being done by a thermal treatment as more fully explained elsewhere herein) 7-denier monofilament ends may be given a twist in the single end in a left or commonly known as a Z-twist, 40 turns per inch. The other end is first preset by thermal treatment and is then given a twist in a right direction or commonly known as an S-twist, 60 turns per inch. The number of turns per inch in either of these twists may be altered to produce varying degrees of contraction as shown in examples hereinafter set forth.

In my method the recoverability and stretch in the fabric made from yarn in accordance with the present invention is entirely due to the high amount of unbridled twist after pre-setting that is left in the yarn, and which in the case of knitting causes the stitches to collapse and become drawn into a compact position. My method does not employ back twisting after the twist is set to produce high elongation in the single end as in the case of Helanca yarns.

Best results have been obtained in my method by presetting the producers yarn and twisting to a high degree of liveliness in the single end, making the twist in the two single ends in the opposite direction. The only back-twisting in my method is What is known to throwsters as a theoretical back-twist of one end necessary to get a ply of the two ends. A degree of liveliness can be rendered to a somewhat lesser degree in single end monofilament yarn by twisting the producers yarn to a high twist then setting and partially backing the twist out before plying. However, this is more costly and not as satisfactory as pre-setting the producers yarn.

A still further object of my invention is to produce a combined thread composed of single ends previously treated in such a manner as to produce a high degree of right and left torque in sufiicient balance to produce a fabric that will hold its shape and not twist to the left or right but will have a high degree of contraction and ability to stretch in all directions.

A foreign thread or size is used only to render the combined thread in a condition suitable for fabrication and to hold the thermoplastic thread such as nylon in an elongated position prior to fabrication.

The type of foreign thread or size used is only confined to one that can be chemically removed after fabrication without detrimental effect to the thermoplastic thread and to its being available commercially in a small enough size to avoid making the combined thread too large, i. e. if a suitably small thread in an acetate rayon becomes commercially available it could be substituted for the silk used in the examples given.

In describing the nylon as a thermoplastic thread, my reason is to prevent the use of my method by substituting for nylon any other synthetic yarn having thermal characteristics that could be set or pre-set according to my method and which would have sufiicient tensile strength for fabrication.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

'1 and 7 denier nylon monofil preset at -1 end 7 denier nylon monofil preset at 15 lbs. 55 Z land 2, '10 and 11 designate single ends of nylon mono:

fils which are first pre-set thermally. The end 10 is then subjected for example to an S-twist of 60 turns per inch but maybe given an S-twist in a range from 10 to 100 turns per inch. The end 11 is subjected for example to a Z-twist-of 40 turns per inch but may be given a Z- twist in a range from 10 to 100 turns per inch. The two twisted ends 10 and 11 are then plied together in a Z- :twist to form the balanced yarn having high stretch characteristics. I

The yarn may be sized to overcome the wildness imparted thereto by'twisting to render same workable for either knitting or weaving. The species of yarn shown in Figure 1 is sized while the species shown in Figure 2 is provided with a carrier yarn 13 which may for example be of a natural fiber such as raw silk or it may be any carrier which could be dissolved out Without affecting the monofils. As set out in the claimsthe size 'or carrier yarn may be referred to broadly as a stabilizer for the twisted monofils to render same workable. Both the size'and yarn must be capable of being dissolved out of the fabric after it is knitted or woven without affecting the plied monofils 10 and 11. For an example of a stabilizer yarn which may be dissolved out without deleterious effect on nylon the patent to J. L. Meade -Number 2,332,738 is referred to.

The two monofils 10 and 11 are provided one with a right twist and the other with a left twist and are plied together witha twist which will produce a balanced yarn having high stretch characteristics.

One of the primary uses of the yarn produced in accordance with this invention is to weave or knit a fabric having a high stretch over an appreciable range as for example the knitting of a full fashioned nylon stocking for women which may be knit one size and which will different size women providing a neat sheer appearance regardless of leg and foot size;

The following are examples of yarns which may be constructed in accordance with the present invention and which possess different degrees of stretch.

Example I 1 end 7 denier nylon monofil preset at 15 lbs. steam pressure for twenty minutes 1 end 7 denier nylon monofil preset at 15 lbs. steam pres- Plied 15 2 sure for twenty minutes 2 1 end 13/15 Japan silk 20 S Example 11 1 end 7 denier nylon monofil preset at 15 lbs.

steam pressure for twenty minutes S 15 lbs. 40 Z Plied Z Plied 10 Z steam pressure for twenty minutes... 1 end 13/15 Japan silk (15 S) Example III 1 end 7 denier nylon monofil preset at 15 lbs.

steam pressure for twenty minutes, 70 S 1 end 7 denier nylon monofil preset at 15 lbs. Plied 10 Z steam pressure for twenty minutes 35 Z Plied 15 2 1 and 13/15 Japan silk a) Example IV 1 end 7 denier nylon monofil preset at 15 lbs.

steam pressure for twenty minutes 55 S Plied 10 S Plled 10 Z steam pressure for twenty minutes"- 1 end 13/15 Japm silk (15 S) sure for twenty minutes stabinzer 'siiji I:IIIIIIIIIIIIIIIIIIIIZIII Example V 1 end 7 denier nylon monofil preset at 15 lbs. steam pressure for twenty minutes 65 1 end 7 denier nylon monofil preset at 15 lbs. steam pressure for twenty minutes 45 Z 1 end 13/15 Japan silk (15 S) Example VI lend nylon monofil preset at 22 lbs. steam for twenty minutes 65 1 end nylon monofil preset at 22 lbs. steam for twenty mmu s Plied 10 Z Example VII 1 end nylon monofil preset at 22 lbsl steam for twenty mmu s 1 and nylon monofil preset at 22 lbs. steam for twenty minutes Stabilizer-size Example VII 1 end 10 denier nylon monofil preset at 15 lbs.

steam pressure for twenty minutes 50 S 1 end 13/15 Japan silk 1 end 10 denier nylon monofil preset at 15 lbs.

steam pressure for twenty minutes 50 Z Example IX 1 end 7 denier nylon monofil preset at 15 lbs. steam pres- Plied 10 Z Z Filed 30 S Plied 20 Z the temperature, steam pressure, and period of exposure may be varied to suit the needs of the end use.

There are other'methodsof thermal settingsuch as dry rather than moist heatwhich may be used with similar results.

have suiiicient stretch to fashionably cover the limbs of In practice I have found Example V to produce a fabric having particularly desirable stretch characteristics and :which when knit into a full fashioned stocking has a highly desirable sheer appearance.

When a silk stabilizer thread is used the silk may be dissolved out by bathing the knit or woven article or fabric in a solution of caustic soda (sodium hydroxide) without detrimental effect to the thermoplastic thread or yarn. By removing the stabilizer, the two twisted and plied monofils contract allowing the stitches of the fabric to collapse, such contraction being inherentlyimparted by my process into the thermoplastic yarn by the above described method of pro-setting and twisting.

In my construction, a right and left torque is imparted to the individual thread, these threads being plied together to render sufficient balance in the finished thread to allow fabrication particularly in knitting using a-single end, single carrier, throughout the processing of a stocking with thisparticular thread. The result is a stocking with high contractibility and suflicient balance to not cause the seam or wales in the fabric to spiral such as a corkscrew. My stocking produces a fabric with high contractibility and without definite pattern of barre or horizontal lines, and when worn, stretches into a clearsheer fabric', without visible'blemishes, when worn.

My stocking accomplishes its contractibility by com binrng two ends of thread with opposite torque in the finished yarn prior to knitting and is knit single carrier from one combined thread, and does not combine the knitting use of of two carrier knitting and opposite torque in the process to render a large proportion of the con tractibility. 7

In using a silk thread stabilizer the silk is not shrunk as a necessary part of my process and any shrinking which may occur is purely incidental.

Referring specifically to Figure 3 a stocking 14 is shown which was knit from yarn produced in accordance with Example IX, a magnified view of the yarn and fabric are shown in. Figure .4. The stocking of Figure 3 stretches over varying leg'sizes: and foot ranges giving a sheer fashionable appearance on the leg of the wearer.

Referring specifically to Figure 5 astocking-IS isshown' which was knit from yarn produced in accordance with Plied 15 Z Example VIII, a magnified view of the yarn and fabric are shown in Figure 6. This stocking was knit in a non run pattern, and also stretches over varying leg sizes and foot ranges giving a shear fashionable appearance on the leg of the wearer.

The yarn of the present invention is not confined to the use of any one monofilament yarn size, for example it may range from 5 to denier. Seven (7) denier is presently not available commercially in quantity and it may be necessary to make production with a larger size yarn. Monofilament yarns may also become available in sizes smaller than seven (7) denier and could be used in my process. 7

The reason for not confining this process to the use of monofilament thread is due to the fact that a multifilament thread may become available of a small enough size (say a size (6) denier 2 filament) that could be fabricated into a similar fabric by the use of my process. Twenty (20) denier multifiilament is the smallest commercially available although samples of multifilament have been produced in 12 denier 4 filament.

Although I have disclosed herein several forms of the invention known to me at this time, I reserve the right to all such modifications and changes as may come Within the scope of the following claims.

What I claim is:

1. A stretchable yarn comprising two ends of thermoplastic monofilament yarn both of said ends being subjected to a thermal preset, one of said ends being twisted in a Z twist, the other of said ends being twisted in an S twist, both said ends being plied together to produce a substantially balanced yarn, having substantially balanced right and left torque for single carrier knitting, and a stabilizer associated with said plied ends to render said yarn workable in the production of a fabric.

2. The process for the production of a stretchable yarn comprising taking two ends of thermoplastic monofilament and subjecting same to an initial thermal preset, twisting one of said preset ends in a Z twist, twisting the other preset end in an S twist, plying both of said twisted preset ends together and subjecting same to a Z twist, to produce a single combined thread having substantially balanced right and left torque for single carrier knitting, and associating a stabilizer with both said plied ends to render said yarn workable in the production of a fabric.

3. The process for the production of a stretchable yarn comprising taking two ends of thermoplastic monofilament, subjecting both of said ends to a thermal preset, twisting one of said ends in a Z twist, twisting the other of said ends in an S twist, playing both said twisted ends together and subjecting same to a Z twist, to produce a single combined thread having substantially balanced right and left torque for single carrier knitting, and associating a yarn stabilizer with said twisted and plied ends to render said yarn workable.

4. The process for the production of a stretchable yarn comprising taking two nylon monofils, subjecting both of said monofils to a thermal preset, twisting one of said monofils in a Z twist, twisting the other of said monofils in an S twist, plying both of said twisted monofils to gether and subjecting same to a Z twist, and associating a stabilizer with said plied and twisted monofils.

5. The process for the production of a stretchable yarn consisting of taking two nylon monofils of a denier range from 5 to 30, subjecting both of said nylon monofils to a thermal preset, twisting one of said monofils in a Z twist a number of turns Within a range of from 10 to 100 not to exceed the breaking point, twisting the other of said monofils in an S twist a number of turns within a range of from 10 to 100 not to exceed the breaking point, plying both of said twisted nylon monofils together and subjecting same to a Z twist a number of turns within a range of from 3 to turns, stabilizing said plied monofils to render the yarn workable.

6. The process for the production of a stretchable yarn consisting of taking two nylon monofils of a denier range of from 5 to '30, subjecting both of said nylon monofils to a thermal preset, twisting one of said monofils in' a. Z twist a number of turns within a range of from 10 to not to exceed the breaking point, twisting the other of said monofils in an S twist a number of turnswithin a range of from 10 to 100 not to exceed the breaking point, plying both of said twisted monofils together and subjecting same to an S twist a number of turns ranging from 3 to 50, and associating a stabilizer with said twisted monofils to render same workable in the preparation of a fabric of said yarn.

7. The process for the production of a stretchable yarn consisting of taking two nylon monofils presetting both monofils, twisting one of said monofils in a -Z twist'40 .turns per inch, twisting the other of said monofils in' an S twist 60 turns per inch, plying both of said twisted monofils with an end of 13/15 raw silk in a Z twist. 15 turns per inch.

8. The process for the production of a stretchable yarn consisting of taking two nylon monofils presetting both of said monofils twisting one of said monofils in a Z twist 40 turns per inch, twisting the other of said monofils in an S twist 60 turns per inch, plying said twisted monofils with a Z twist and subjecting said twisted monofils to a size stabilizer.

9. A stretchable fabric knit from yarn in accordance with claim 1.

10. A stretchable full fashioned stocking knit from yarn in accordance with claim 1.

11. A stretchable fabric knit from yarn produced in accordance with claim 2.

12. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 2.

13. A stretchable fabric knit from yarn produced in accordance with claim 3.

14. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 3.

15. A stretchable fabric knit from yarn produced in accordance with claim 4.

16. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 4.

17. A stretchable fabric knit from yarn produced in accordance with claim 5.

18. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 5.

19. A stretchable fabric knit from yarn produced in accordance with claim 6.

20. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 6.

21. A stretchable fabric knit from yarn produced in accordance with claim 7.

22. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 7.

23. A stretchable fabric knit from yarn produced in accordance with claim 8.

24. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 8.

25. A stretchable fabric knit from yarn in accordance with claim 1 wherein said stabilizer has been removed.

26. A stretchable full fashioned stocking knit from yarn in accordance with claim 1 wherein said stabilizer has been removed.

27. A stretchable fabric knit from yarn produced in accordance with claim 2 wherein said stabilizer has been removed.

28. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 2 wherein said stabilizer has been removed.

29. A stretchable fabric knit from yarn produced in accordance with claim 3 wherein said yarn stabilizer has been dissolved out.

30. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 3 wherein said yarn stabilizer has been dissolved out.

31. A stretchable fabric knit from yarn produced in accordance with claim 4 wherein s aid stabilizer has been dissolved out.

- 32. A stretchable mu fashioned stocking knitfrom yarn produced in accordance with'claim 4 wherein said "5 stabilizer has been dissolved out.

stabilizer has been dissolved out.

33. A stretchable fabric knit from yarn produced in accordance with claim 6 wherein said stabilizer has been dissolved out.

34. A stretchable full fashioned stocking knit from'yarn 'produced in accordance with claim 6' wherein the stabilizer has been dissolved out.

3 5. A stretchable fabric knit from yarn produced in accordance with claim 7 wherein said raw silk has been dissolved out.- t

36. A stretchable full fashioned stocking knit from yarn produced in accordance with claim 7 wherein the raw silk has been dissolved out. 7

37. A stretchable fabric knit from yarn produced in been dissolved out. 38. A stretchable full yarn produced in accordance with claim 8 fashion ed stocking knit from wherein; the

References Cited the file of patent i; f a

UNITED STATES PATENTS 1.

Benger Ma 1,1900 Billion Aug."14,- 1951 Nenrnager June 16,: 1953 Brooks June 1, I954 Leath et al. June 28, 1955 Leath et al. Nov. 27; 19 56 Burleson 'Nov. 27,1956

FOREIGN PATENTS v I V a Great Britain Mar. 7, 193$ 

